Polycarbonamides resistant to acid dyes and containing terminal naphthyl disulfonated radicals



United States Patent "ice 3 438,949 POLYCARBONAMIDES RESISTANT T0 ACIDDYES AND CONTAINING TERMINAL NAPHTHYL DI- SULFONATED RADICALS LawrenceW. Crovatt, Jr., Raleigh, N.C., assignor to Monsanto Company, acorporation of Delaware No Drawing. Filed Oct. 21, 1965, Ser. No.500,358 Int. Cl. C08g /20, 53/14 US. Cl. 260-78 4 Claims ABSTRACT OF THEDISCLOSURE Fiber-forming linear polycarbonamides modified to containcertain terminal naphthyl disulfonated radicals as an integral part ofthe polymer chain possess excellent acid dye-resistant properties.Fibers formed from these polycarbonamides may, for example, be combinedwith standard polycarbonamide fibers to provide a fabric which isdyeable in a single dye bath to different colors or color tones.

This invention relates to fiber-forming synthetic polymeric materialsand the shaped articles produced therefrom. More particularly, thisinvention relates to novel fiber-forming synthetic linearpolycarbonamides and the shaped articles produced therefrom which areparticularly resistant to acid type dyes.

Although textile fibers obtained from fiber-forming polycarbonamidesheretofore known are of great value, they are deficient in dyeingproperties in that they all possess the same acid dyea'blecharacteristic, and each type will dye to a single shade only. This is adistinct disadvantage since it eliminates the possibility of obtainingother desirable color effects Where some of the fibers do not absorb dyeor absorb less dye. It is desirable, therefore, to producepolycarbonamides which have acid dyeresist characteristics so that bycombining such polycarbonamides with standard polycarbonamides invarying amounts it would be possible to produce polycarbonamide articleswhich are dyeable to different tones of the same color. Heretofore,additives employed for this purpose have not been found to be entirelysatisfactory due to their ability to impart only a limited amount ofacid dyeresistance to the fibers. For example, US. Patent 3,039,- 990discloses fibers treated with alkali metal dicarboxybenzenemonosulfonates. While these additives serve to make the fibers receptiveto basic dyes, they do not impart a sufiicient acid dye-resist characterto the fibers to make them commercially acceptable for use with aciddyes in the production of a wide range of off-shade fabrics.

It is an object of the present invention to provide novel and usefulfiber-forming synthetic linear polycarbonamides.

Another object is to provide shaped articles such as textile fibers,produced from such polycarbonamides, the said articles having superioracid dye-resist properties. A further object is to provide a process forthe production of polycarbonamides from which shaped articles havingsuperior acid dye-resist properties can be prepared.

These and other objects will become apparent in the course of thefollowing specification and claims.

The polycarbonamides of the present invention are useful in theproduction of shaped articles by extrusion, molding or casting in thenature of yarns, fabrics, fibers, pellicles, bearings, ornaments, or thelike. They are particularly useful in the production of textile fibers.

The present invention provides a novel fiber-forming synthetic linearpolycarbonamide wherein recurring carbonamide linkages are an integralpart of the polymer chain and containing as a component part of thepolymer 3,438,949 Patented Apr. 15, 1969 chain between about 0.05 and2.0 mole percentage and preferably between about 0.1 and about 1.0 molepercentage, based on the molecular weight of the polycarbonamide, ofunits of the structure:

wherein Z is a member of the class consisting of o X and --l I- X is amember of the class consisting of hydrogen and lower alkyl, M is analkaline earth metal and n is a number from zero to 6 inclusive with theproviso that when then n is at least 1.

As used herein, the term molecular weight of the polycarbonamide" refersto the molecular weight of one repeating unit of the polycarbonamide.Thus, the molecular weight of polyhexamethylene adipamide would be 226which is the molecular weight of one repeating unit having the formulawherein R is a divalent hydrocarbon radical, and a diamine having theformula )5 X HNRI\II-H (0) wherein X and R are as defined above and (B)a monoaminocarboxylic acid having the formula:

i HN-R-C 0 0H (d) wherein X and R are as defined above, in the presenceof a monofunctional disulfonated compound having the formula:

. (CH2) HZY S03 M :iS wherein n, Z and M are as defined above and Y is amember of the class consisting of hydrogen, OH, Cl, OR, R being amonovalent hydrocarbon radical such that ROH is volatile below thedecomposition temperature of the polycarbonamide formed.

The nature of the radical R in the acid, the diamine or the amino acidis not critical. Preferably it is a divalent hydrocarbon radicalcontaining no more than about 20 carbon atoms. Typical acids of theclass illustrated by the formula designated (1)) above are oxalic,adipic, suberic, pimelic, azelaic, sebacic, brassylic, octadecanedioic,undecanedioic, glutaric, tetradecanedioic, p-phenylene diacetic,isophthalic, terephthalic, hexahydroterephthalic, and the like, andmixtures thereof.

Typical suitable diamines of the class illustrated above by the formuladesignated (c) above are ethylenediamine, propylenediamine,tetramethylenediamine, pentamethylenediamine, hexamethylenediamine,octamethylenediamine, decamethylenediamine, p-xylylenediamine,p-phenylenediamine, hexahydro-p-phenylenediamine, bis(4-aminocyclohexyl)methane, piperazine, dimethylpiperazine,tetramethylpiperazine, the N,N-dimethyl, the N,N-diethyl and theN,N-diisopropyl derivatives of the above, and the like, as well asmixtures thereof.

Typical suitable amino acids of the class represented by the formuladesignated (-d) above are 6-aminocaproic acid, 9-aminononaoic acid,ll-aminoundecanoic acid and 17-arninoheptadecanoic acid.

In place of the above dibasic carboxylic acids, diamines, and aminoacids, the amide-forming derivatives thereof can be employed to formfiber-forming polymers. Amide-forming derivatives of the dibasiccarboxylic acids comprise the monoand di-ester, the anhydride, themonoand di-amide, and the acid halide. Amide-forming derivatives of thedamines include the carbamate and the N-formyl derivatives.Amide-forming derivatives of the amino acids include the ester, theanhydride, amide, lactam, acid halide, N-formyl derivative, carbamate,and, in the presence of water, the nitrile.

As indicated above the compounds found useful in the practice of thisinvention are characterized by two sulfonate groups and oneamide-forming group attached to a naphthalene ring and are representedby the formula:

II C calcium -1-carb0xy-naphthalene disulfonate, barium-2-carboxy-naphthalene disulfonate, magnesium-Z-carboxynaphthalenedisulfonate, strontium-l-carboxy naphthalene disulfonate, and the like,when Z is calcium-l-methylamino-naphthalene disulfonate, barium-2-ethylamino-naphthalene disulfonate,magnesium-l-methylamino-naphthalene disulfonate,strontium-2-ethylaminonaphthylene disulfonate, and the like.

The polycarbonamides of this invention are prepared by procedures wellknown in the art and commonly employed in the manufacture of simplepolyarnides. That is, the reactants are heated at a temperature of from180 C. to 300 C. and preferably from 200 C. to 295 C. until the producthas a sufiiciently high molecular weight to exhibit fiber-formingproperties, which properties are reached when the polyamide has anintrinsic viscosity of at least 0.4. The reaction can be conducted atsuper-atmospheric, atmospheric, or sub-atmospheric pressure. Often it isdesirable, especially in the last stage of the reaction, to employconditions, e.g., reduced pressure, which will aid in the removal of thereaction byproducts. Preferably the reaction is carried out in theabsence of oxygen, for example, in an atmosphere of nitrogen.

Intrinsic viscosity as employed herein is defined as L' :2 (logaNr inwhich N is the relative viscosity of a dilute solution of the polymer inm-cresol in the same units at the same temperature and C is theconcentration in grams of polymer per 100 cc. of solution.

The amount of additive which may be present as a component part of thepolymer chain of the polycarbonamides of this invention may varydepending upon the type of polymer desired and the particular shapedarticle in which it is to find its end use. It has been found necessaryto employ between about 0.05 and 2.0 mole percentage based on themolecular weight of the polycarbonamide. At least 0.05 mole percentageof additive is required in order that a significant level of aciddye-resist properties be obtained. It has been found that the bestresults are obtained when between about 0.1 and about 1.0 molepercentage of additive based on the molecular weight of thepolycarbonamide are employed. Amounts greater than 2.0 mole percentagehave an adverse effect on the viscosity of the polycarbonamide produced.Since the additives employed in this invention contain only onefunctional group, i.e. one carboxyl or one amino group, it can be seenthat they react in such a manner as to terminate the polymer chain ofthe polycarbonamide. This type of reaction is similar to the reactionwhich occurs upon the addition of additives which are termed by the artas chain terminators or viscosity stabilizers. Thus, the greater amountof additive which is employed in the present invention, the shorter willbe the polymer chain of the polycarbonamide and the lower will be theviscosity of the polycarbonamide. As noted above, it has been foundpreferable to employ amounts of additives between about 0.1 and 1.0 molepercentage since when employing such amounts the polycarbonamideproduced has been found to possess excellent acid dye-resist propertiesand to have a viscosity in the fiber-forming range.

In order to illustrate the invention and the advantages thereof withgreater particularity, the following specific examples are given, it isto be understood that they are intended to be only illustrative and notlimitative. Parts are given by weight unless otherwise indicated.

EXAMPLE I This example illustrates the preparation of a conventionalpolycarbonamide, namely, polyhexa-methyleneadipamide. This polymer andthe fiber produced therefrom are to be used as a standard comparisonwith the modified polycarbonamides of the present invention.

To a stainless steel evaporator there was added 8.47 moles of watercontaining 0.562 mole of hexamethylene diammonium adipate salt dissolvedtherein. The unit was purged with nitrogen and then pressurized to 13pounds per square inch gauge. The salt solution was then heated to 137C. with continuous removal of steam condensate. At this point the saltconcentrate was piped under pressure into a stainless steel highpressure autoclave which had been purged previously with nitrogen. Inthis reactor, which contained a stirrer for agitation, the pressure wasimmediately raised to 250 pounds per square inch gauge and thetemperature raised to 22 C. The steam was removed until the polymer melttemperature reached 243 C. At this point the reactor pressure wasgradually reduced over a 25 minute period to atmospheric pressure andthe polymer melt allowed to equilibrate for 30 minutes at 278 C.

The finished polymer so produced was melt spun at 280 C. through a 13hole spinnerette yielding white multifilament yarn. These yarns weredrawn over hot pins C.) at maximum draw ratio of 5.65 times theiroriginal length.

Dyeing of these yarns was carried out by immersing in an acid dye bathcontaining 3 percent based on the weight of the yarn of Scarlet 4RAconc. CF (C1. acid red 18) and 1.2 percent formic acid. The weight ratioof dye bath to fiber was maintained at 40:1 and dyeing was conducted for2 hours at 100 C. and at a pH of 3.1. These yarns absorbed 1.25 percentdyestuif.

EXAMPLE II Barium 2 carboxy-naphthalenedisulfonate was prepared bytreating an aqueous solution of di(potassiumsulfonate)-naphthalene-2-carboxylic acid with saturating quantities ofbarium chloride. Precipitation of barium salt occurred and was isolatedby filtration.

The procedure of Example I was repeated with the exception that theabove prepared barium-Z-carboXy-naphthalene disulfonate, in an amountsufiicient to provide a finished poly-hexamethylene adipamide containing0.56 mole percent additive was added along with the salt into theautoclave. This modified polymer thus produced was melt spun at 280 C.in the form of a 13 multifilament white yarn. These yarns were drawnover hot pins (90 C.) at a maximum draw ratio of 5.35 times theiroriginal length. These yarns were found to absorb 0.64 percent Scarlet4RA Conc. CF (C.I. acid red 18) acid dyestuif when dyed under theidentical procedure and with the same dye bath composition as outlinedin Example I. This dye absorption represents very nearly 48.7 percentdye-resist character over the standard poly-hexamethylene adipamide.

As can be seen from the above results, fibers made from thepolycarbonamides of the present invention possess a resistance toacid-type dyes. This enables manufacturers to produce fibers having thesame basic polycarbonamide molecular structure as conventionalpolycarbonamides but difierent afiinitives for acid dye. This in turnoffers dyeing diversification for fabric color-on-white effects andtoneon-tone etfects heretofore not readily obtainable.

I claim:

1. A fiber-forming synthetic linear polycarbonamide wherein recurringcarbonamide linkages are an integral part of the polymer chain andcontaining as a component part of the polymer chain between about 0.05and 2.0 mole percentage, based on the molecular Weight of thepolycarbonamide of units of the structure:

S0 M 03S 6 wherein Z is a member of the class consisting of i C and N Xis a member of the class consisting of hydrogen and lower alkyl, M is analkaline earth metal and n is a number from zero to 6 inclusive with theproviso that when Z is SO; B3 Oils 4. A textile fiber consisting of thepolycarbonamide as defined in claim 1.

References Cited UNITED STATES PATENTS 3,039,990 6/1962 Huffman 260783,142,662 7/1964 Hufiman 26078 3,184,436 5/1965 Magat 26078 3,296,204 1/1967 Caldwell 26078 3,328,484 6/1967 Lugaz et a1. 26078 WILLIAM H.SHORT, Primary Examiner.

H. D. ANDERSON, Assistant Examiner.

US. Cl. X.R.

